Watch Knock-Out Girl

From her heartless aunt, Ryuko learns of her sister's death and of her disownment from the family. Following this, Ryuko is sexually harassed at work, and end up being fired. A man named Kito approaches Ryuko and reveals the truth about how her sister died in a suicide game, and invites her to play the game too. Ryuko gets a tattoo on her fist, and transforms herself into a knock-out thief...